The present application teaches a circuit for use in reducing power consumption of a real time clock in a computer system.
When a personal computer is turned off, an on-board battery, e.g. a 3-volt lithium battery, may still power certain circuits in the computer. For example, a real time clock often still maintains the time using battery power when the primary computer power supply goes offline.
The smaller transistors that are now used to make such circuits in order to fit more transistors on a substrate, often have higher leakage currents. These transistors consume undesired current when they are biased to the “off” state. This increases the DC load that is placed on the battery, when the computer power supply is off due to off state current, which can cause the battery to deplete more quickly.